Vertebrobasilar ectasia is a rare cause of typical trigeminal neualgia. In a recently published large series only thirty-one (2%) of 1404 consecutive patients with vascularly determined neuralgia were found to have vertebrobasilar compression. We present three patients with trigeminal neuralgia caused by vertebrobasilar ectasia, who were evaluated with high resolution magnetic resonance imaging (MRI). MRI studies provided accurate information on the anatomical location and course of the ectatic vessel in the cerebellopontine angle and the caused mass effect on the brainstem...